1. Technical Field
The present disclosure relates to a vehicle headlamp. More particularly, the present disclosure relates to a technical field that secures a sealing property in a lamp outer casing and improves a heat-radiation property by fixing a light source unit to a lamp housing while heat sinks are positioned on the outside of a lamp outer casing.
2. Related Art
As a vehicle headlamp, there is, for example, a vehicle headlamp where a lamp unit is disposed in a lamp outer casing including a lamp housing and a cover. The lamp unit includes a lens unit that includes a projection lens projecting light emitted from a light source to the front side and a lens holder holding the projection lens.
As this vehicle headlamp, there is a vehicle headlamp that includes heat sinks for radiating heat generated during the drive of a light source, that is, the emission of light from a light source (see e.g., JP-A-2008-257959).
Further, a vehicle headlamp is provided with an aiming adjustment mechanism that adjusts the direction of an optical axis at the time of the shipment of the vehicle, the inspection of the vehicle, and the like. Accordingly, when an aiming operation shaft of the aiming adjustment mechanism is rotated about an axis, a lamp unit is rotated in a vertical or lateral direction, and thus the direction of an optical axis is adjusted.
In the vehicle headlamp disclosed in JP-A-2008-257959, a lens unit and heat sinks are mounted on a frame disposed in a lamp outer casing and the heat sinks protrude rearward from a protrusion hole formed at a lamp housing. An aiming operation shaft is engaged with the frame. Accordingly, the frame, the lens unit, and the heat sinks are tilted integrally with each other by the rotation of the aiming operation shaft, so that the direction of an optical axis is adjusted.
In the vehicle headlamp, heat generated during the drive of a light source is radiated to the outside through the heat sinks protruding rearward from the lamp housing. Accordingly, a good heat-radiation property is secured. Since the heat generated during the drive of the light source is radiated to the outside, the rise of the temperature of the light source is suppressed and the normal drive state of the light source is secured.
Meanwhile, in the vehicle headlamp disclosed in JP-A-2008-257959, the heat sinks are tilted together with the lens unit when aiming adjustment is performed. For this reason, there is a concern that a gap is formed between the lamp housing and the heat sink.
If a gap is formed between the lamp housing and the heat sinks, a sealing property in the lamp outer casing deteriorates. For this reason, there is a possibility that the amount of light irradiated forward is reduced or the smooth operation of each part is hindered by the penetration of dust or moisture into the lamp outer casing.